private void liberarCola() {
// La cola común tiene prioridad, así evitamos el interbloqueo
if (colaComun.hasQueuedThreads()) {
colaComun.release();
} else {
colaInicial.release();
}
}
/**
* Overrides World<T> newGame(char). Shoots a MoveInfo with null piece and null location to the
* CheckerGame if the game is still running. If the game has ended, directly changes the
* CheckerGame's game status for CheckerRunner to detect.
*
* @param a the new game status
*/
public void newGame(char a) {
newGame = a;
playerPiece = null;
setPlayerLocation(null);
if (!lock.hasQueuedThreads()) // if the game has ended
{
game.newGame(a);
}
super.newGame(); // World's newGame() disposes the frame
}
// Synchronizes two threads execution points.
// Basically any thread could get scheduled to run and
// it is not possible to know which thread reaches expected
// execution point. So whichever thread reaches a execution
// point first wait for the second thread. When the second thread
// reaches the expected execution point will wake up
// the thread which is waiting here.
void stopOrGo() {
semaphore.acquireUninterruptibly(); // Thread can get blocked.
if (!waiting) {
waiting = true;
// Wait for second thread to enter this method.
while (!semaphore.hasQueuedThreads()) {
try {
Thread.sleep(20);
} catch (InterruptedException xx) {
}
}
semaphore.release();
} else {
waiting = false;
semaphore.release();
}
}
